双源CT冠状动脉成像在心房纤颤患者中的应用体会

目的:探讨应用双源CT时心房纤颤(AF)患者进行冠状动脉成像的可行性及心率对图像质量和重建时相的影响.方法:对29例临床可疑冠心病的AF患者进行双源CT增强扫描.29例患者按扫描时平均心率分成2组,慢心率组(＜80次/分)12人,快心率组(≥80次/分)17例.利用回顾性心电门控重建图像,以4级记分评价图像质量.比较慢心率组与快心率组的图像质量评分采用t检验.结果:慢心率组和快心率组的图像质量评分分别为(1.26±0.55)和(1.49±0.77)分,差异有统计学意义(t=-3.433,P＜0.01).慢心率组的最佳重建时相约一半出现在舒张期,快心率组的最佳重建时相多出现在收缩期.总体上29例患者97.4%的冠状动脉节段可以评价.结论:拥有高时间分辨力的双源CT能够为大部分房颤患者提供可评价的图像,心率对图像质量和重建时相有影响.     

Effect of Heart Rate and Coronary Calcification on the Diagnostic Accuracy of the Dual-Source CT Coronary Angiography in Patients with Suspected Coronary Artery Disease

Objective

To evaluate the diagnostic accuracy of a dual-source computed tomography (DSCT) coronary angiography, with a particular focus on the effect of heart rate and calcifications.

Materials and Methods

One hundred and nine patients with suspected coronary disease were divided into 2 groups according to a mean heart rate (< 70 bpm and ≥ 70 bpm) and into 3 groups according to the mean Agatston calcium scores (≤ 100, 101-400, and > 400). Next, the effect of heart rate and calcification on the accuracy of coronary artery stenosis detection was analyzed by using an invasive coronary angiography as a reference standard. Coronary segments of less than 1.5 mm in diameter in an American Heart Association (AHA) 15-segment model were independently assessed.

Results

The mean heart rate during the scan was 71.8 bpm, whereas the mean Agatston score was 226.5. Of the 1,588 segments examined, 1,533 (97%) were assessable. A total of 17 patients had calcium scores above 400 Agatston U, whereas 50 had heart rates ≥ 70 bpm. Overall the sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) for significant stenoses were: 95%, 91%, 65%, and 99% (by segment), respectively and 97%, 90%, 81%, and 91% (by artery), respectively (n = 475). Heart rate showed no significant impact on lesion detection; however, vessel calcification did show a significant impact on accuracy of assessment for coronary segments. The specificity, PPV and accuracy were 96%, 80%, and 96% (by segment), respectively for an Agatston score less than 100% and 99%, 96% and 98% (by artery). For an Agatston score of greater to or equal to 400 the specificity, PPV and accuracy were reduced to 79%, 55%, and 83% (by segment), respectively and to 79%, 69%, and 85% (by artery), respectively.

Conclusion

The DSCT provides a high rate of accuracy for the detection of significant coronary artery disease, even in patients with high heart rates and evidence of coronary calcification. However, patients with severe coronary calcification (> 400 U) remain a challenge to diagnose.     

64层螺旋CT冠状动脉成像诊断冠状动脉狭窄的初步探讨

目的：探讨64层螺旋CT（MSCT）冠状动脉成像对冠状动脉狭窄的诊断价值。方法：53例冠心病患者同期均行64层螺旋CT冠状动脉成像和常规冠状动脉造影（CCA）,以CCA的诊断结果作为金标准,采用美国心脏协会冠状动脉改良分段法,分析745个冠状动脉节段MSCT图像质量及对冠状动脉狭窄的显示情况,得出有意义病变（冠状动脉狭窄率≥500%）MSCT诊断的正确性,并分析钙化对其影响。结果：587个冠状动脉节段图像可以满足诊断要求,158个节段因运动伪影（27个节段）或管壁严重钙化（131个节段）无法进行血管评价。MSCT诊断冠状动脉狭窄的敏感度为93．4％、特异度为97．9％、阳性预测值为93．9％、阴性预测值为97．7％。钙化积分≥1000的患者,MSCT诊断冠状动脉狭窄的特异度、敏感度、阳性预测值、阴性预测值分别为74％、82％、68％、96％。结论：64层螺旋CT冠状动脉成像是一种快速、安全、无创的检查方法,与常规冠状动脉造影检查结果有较好的一致性,可以作为临床怀疑冠心病患者的首选检查方法。     

64MDCT冠状动脉成像在冠心病诊断中的应用价值

目的探讨64层螺旋CT冠状动脉成像在冠心病诊断中的应用价值。方法随机选择我院2010年10月～2011年12月46例由于胸痛、胸闷就诊的患者,分别给予64层螺旋CT冠状动脉成像与选择性冠状动脉造影,以选择性冠状动脉造影检查的结果为“金标准”,分析64层螺旋CT冠状动脉成像在冠心病诊断中的敏感性、特异性及准确率。结果MDCTCA共检查节段586个,直径在1．5mm以上有504个,检出狭窄程度≥50％的28例,漏诊1例,误诊2例。与冠状动脉造影检查结果相比,64层螺旋CT冠状动脉成像检查的敏感性为96．3％（26／27例）,特异性为89．5％（17／19例）,准确性为93．5％（43／46例）,阳性预测值为92．9％（26／28）,阴性预测值为94．4％（17／18）,差异无统计学意义（P〉0．05）。结论64层螺旋CTCA具有无创、安全、经济且操作简便的优点,对冠状动脉病变诊断具有良好的敏感度和特异性,是一种可广泛应用于冠心病的筛选和诊断的检查方法。     

高时间分辨率宽体探测器CT对心房颤动患者冠状动脉造影可行性研究

目的 探讨高时间分辨率宽体探测器CT应用于心房颤动患者冠状动脉CT造影(CCTA)的可行性.方法 以20例窦性心律患者CCTA图像为对照,回顾性分析20例房颤患者CCTA图像.由2名放射诊断医师采用盲法对40例图像进行评分(3分制),记录两组患者有效辐射剂量(ED).结果 20例房颤患者CCTA图像均符合诊断标准,达到临床要求.房颤组得分1.12 ±0.32,窦性心律组得分1.10 ±0.28,两组间主观评分差异无统计学意义(P=0.278).为保证房颤患者检查成功率,房颤组检查间隔一个心动周期连续扫描两次,获得两套数据,辐射剂量相应翻倍.房颤组ED(3.41±1.23)mSv,窦性心律组ED(1.91 ±0.85) mSv.结论 高时间分辨率宽体探测器CT可应用于心房颤动患者CCTA,且成功率高.     

256层螺旋CT冠状动脉成像与冠状动脉造影对比分析

目的 探讨256层螺旋CT冠状动脉成像(CTA)在冠心病诊断中的价值并与冠状动脉造影(ICA)结果比较.资料与方法 回顾性分析93例临床疑似和诊断为冠心病患者的影像资料,行256层螺旋CTA和常规ICA.管腔狭窄程度≥50％作为明显狭窄的诊断结果,检查结果与常规ICA结果对比分析,共分析了93例患者的372支血管共1349个可评估血管节段,ICA共发现215处狭窄.采用受试者工作特征(ROC)曲线下面积(AUC)评价CTA相对于ICA诊断的准确性.结果 基于患者分析中,CTA对冠状动脉狭窄诊断的AUC为0.767(95％可信区间为0.578～0.956),敏感性为98.8％,特异性为54.5％,阳性预测值(PPV)为94.2％,阴性预测值(NPV)为85.7％;基于血管分析中,CTA对冠状动脉狭窄诊断的AUC为0.921(95％可信区间为0.888 ～0.954),敏感性为93.4％,特异性为90.8％,PPV为83.1％,NPV为96.6％;基于血管节段分析中,CTA对冠状动脉狭窄诊断的AUC为0.948(95％可信区间为0.927～0.969),敏感性为93.0％,特异性为96.6％,PPV为83.7％,NPV为98.6％.CTA对心率＞70次/min和心率≤70次/min患者的冠状动脉狭窄诊断的AUC分别为0.951(95％可信区间为0.929 ～ 0.974)和0.964(95％可信区间为0.927 ～1.000).结论 256层螺旋CTA作为无创的检查对血管狭窄诊断的敏感性高,有较高的预测价值;检查受心率影响较小,无需控制心率,可以作为冠心病患者早期筛查的可靠方法.     

16层螺旋CT血管成像诊断脾动脉瘤的价值

目的:探讨16层螺旋CT血管成像(16-MSCTA)诊断脾动脉瘤(SAA)的价值。材料和方法:回顾性分析17例SAA的16-MSCTA表现。后处理均采用容积再现法(VR)、表面覆盖法(SSD)、最大密度投影(MIP)、多平面重组(MPR)及曲面重组(CPR)等后处理技术,以VR作为诊断的主要依据,其它重组方法作为补充。结果:17例SAA41个瘤体中,25个位于脾门,15个伴瘤体钙化。单发7例和多发10例。VR、SSD、MIP、MPR及CPR均能显示SAA,以VR显示最佳。结论:16-MSCTA是一种有效的无创的检查手段,能准确地显示脾动脉瘤的存在及病理改变,是诊断和随访脾动脉瘤的首选方法。     

Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

Objective

To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode.

Materials and Methods

Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 ± 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed.

Results

There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 ± 0.306 [group A] vs. 1.084 ± 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 ± 0.16 mSv in group A and 7.1 ± 1.05 mSv in group B (p = 0.001).

Conclusion

In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.     

心房颤动患者的64层螺旋CT冠状动脉成像的初步临床研究

目的 探讨64层螺旋CT在心房颤动患者冠状动脉CT血管成像(CTA)中的应用价值.方法 分析31例心房颤动患者的冠状动脉CTA图像质量,利用血管分析软件判断血管有无狭窄并测量狭窄率,其中10例患者的冠状动脉CTA结果与冠状动脉造影(CAG)结果进行了对照分析.对于不同心率患者图像质量的比较分析采用多个独立样本(等级资料)的非参数秩和榆验.结果所有患者均采用绝对值时间法重组心脏容积数据.对31例患者中364段血管节段进行成像质量分析:心率为47～69次/min组图像质量为优、良、中和差的血管节段数分别为85、41、5和8个,心率为70～79次/min组分别为63、16、13和15个,心率为80～105次/min组分别为46、25、23和24个,3组间成像质量差异有统计学意义(H=22.08,P＜0.01).10例与CAG进行对照,共分析冠状动脉血管125段,CTA诊断血管狭窄程度≥50%的敏感度为85.0%(17/20),特异度为95.2%(100/105),阳性预测值为77.3%(17/22),阴性预测价值为97.1%(100/103).冠状动脉CTA低估了3段血管的病变,过度评价了5段血管.结论64层螺旋CT对心房颤动患者进行冠状动脉CTA检查具有一定的临床价值.     

16层CT显示冠状动脉狭窄与导管法造影的对照研究

目的:评价16层CT在显示冠状动脉狭窄中的价值和限度。方法:55例临床诊断或可疑冠心病的患者做16层CT冠状动脉成像检查(回顾性心电门控、0.5s螺旋扫描、单或双扇区重建算法和静脉注射对比剂),其检查结果与导管法冠状动脉造影对照。结果:在55例患者冠状动脉的568节段(血管直径≥2mm)中,CT图像能够满足管腔评价者为492节段(占86.6%),其中16层CT显示中度或中度以上狭窄(≥50%)的敏感度和特异度分别为87.5%和97.2%,阳性和阴性预测值分别为82.4%和98.1%;16层CT显示高度狭窄(≥75%)的敏感度和特异度分别为91.6%和98.7%,阳性和阴性预测值分别为 84. 6%和 99. 3%。结论:如果冠状动脉 CT 图像能够满足管腔评价, 16 层 CT 显示冠状动脉狭窄(≥50%)的准确性很高。在冠状动脉中、高度狭窄的初步诊断以及介入治疗的筛选方面,16 层 CT可以部分取代传统的导管法冠状动脉造影。     

64排螺旋CT冠脉成像中双筒注射技术探讨

目的:探讨64排螺旋CT冠状动脉成像中,应用双筒注射技术消除上腔静脉伪影的作用。方法:182例疑冠心病的患者行64排螺旋CT冠状动脉成像,采用双筒高压注射器,高速注射对比剂后立刻以相同流率注射30~50ml生理盐水。评价上腔静脉伪影对图像质量的影响,图像质量分优、良和差3个等级。结果:本组中CT冠脉成像质量优者占85%,良占14%,差占1%。结论:通过采用双筒高压注射器,可消除上腔静脉和右心房内潴留对比剂而产生的伪影,提高64排螺旋CT冠状动脉成像质量。     

64层螺旋CT冠状动脉成像在心肌桥和壁冠状动脉诊断中的价值

目的探讨64层螺旋CT冠状动脉成像对心肌桥(MB)的诊断及其临床价值。资料与方法1422例患者均行64层CT扫描,所有数据传至工作站进行重组和后处理,观察有无MB,测量MB的长度、厚度、壁冠状动脉狭窄程度等。所有MB病例均行冠状动脉造影(CAG)检查并与CT结果对比。结果共发现104例119段MB,平均长度及厚度分别为(5.0±2.7)mm、(2.0±1.6)mm,壁冠状动脉狭窄程度为(31±17)%。104例MB患者CAG发现42例44段MB,其长度、厚度与CT结果存在明显差异。结论64层CT对MB和壁冠状动脉清晰显示,有特殊的临床价值。     

Myocardial Bridging of the Left Anterior Descending Coronary Artery: Depiction Rate and Morphologic Features by Dual-Source CT Coronary Angiography

Objective

To evaluate the depiction rate and morphologic features of myocardial bridging (MB) of the left anterior descending coronary artery (LAD) using dual-source CT (DSCT).

Materials and Methods

CT scans from a total of 1,353 patients who underwent DSCT were reviewed retrospectively for LAD-MB. Seventy-eight patients were excluded due to poor image quality or poor enhancement of the coronary artery. The length and depth of the MB were analyzed and classified as superficial or deep with respect to the depth (≤ 1 or > 1 mm) of the LAD tunneled segment. Superficial MB was subdivided into complete or incomplete types according to full or partial encasement of the myocardium.

Results

Of the 1,275 patients included in this study, 557 cases of MB were found from 536 patients (42%). Superficial MB was observed in 368 of 557 (66%) cases, and deep MB was seen in 189 of 557 (34%) cases. Superficial MB showed 2 types: complete (128 of 368, 35%) and incomplete (240 of 368, 65%). The mean length of a tunneled segment for superficial MB was 16.4 ± 8.6 mm. The mean length and depth of a tunneled segment for deep MB were 27.6 ± 12.8 mm and 3.0 ± 1.4 mm, respectively. The incidence of atherosclerotic plaques in a 2-cm-long segment proximal to MB was 16%.

Conclusion

The depiction rate of LAD-MB using DSCT in a large series of patients was 42%, with two-thirds of MB segments being the superficial type.     

3.0 T MR对比增强全心冠状动脉成像与CTA的对照研究

目的评价3.0TMR对比增强全心冠状动脉成像(CE-CMRA)对冠状动脉病变的诊断价值。资料与方法搜集21例已行冠状动脉CTA(CCTA)检查病例,行3.0TMRCE-CMRA,以CCTA为对照,按照AHA9段法评价冠状动脉显示情况。结果 21例患者顺利完成MRI检查,平均扫描时间为(10.6±2.3)min,CE-CMRA可评价冠状动脉节段164个。冠状动脉近段及中段显示良好,与CCTA比较差异无统计学意义(P>0.05)。12例有意义狭窄(狭窄程度(50%),CE-CMRA显示10例。在狭窄段长度比较中两者差异无统计学意义(P>0.05)。狭窄程度比较,CE-CMRA较CCTA偏高。结论 CE-CMRA对冠状动脉近、中段显示良好,对狭窄的评估可靠,可作为冠状动脉近、中段有意义狭窄的一种筛选手段。对不适于CCTA检查的病例,CE-CMAR可作为一种好的替代方法。但对冠状动脉远段及小分支狭窄的评估有一定限度。     

64层CTCA与CAG对心肌桥和壁冠状动脉诊断的对比分析

目的探讨64层CT冠状动脉成像(64 CTCA)对心肌桥(MB)和壁冠状动脉(MCA)的诊断价值。资料与方法回顾性分析行64 CTCA与冠状动脉造影(CAG)检查的527例患者资料,测量CTCA发现MB的长度、厚度和MCA狭窄程度,与CAG表现对比分析。结果 527例患者经64 CTCA检出MB 118例(22.4%),而该118例MB患者经CAG仅检出48例(9.1%),两者对比差异有统计学意义(P<0.05)。64 CTCA发现MB的平均长度及厚度分别为(6.1±2.5)mm、(2.5±1.6)mm,MCA狭窄程度为(47.3±11.3)%;与CAG检出的MB长度与MCA狭窄程度对比,差异均有统计学意义(P<0.05)。结论 64 CTCA对MB和MCA的诊断特异性较高,有重要的临床价值。     

The Diagnostic Accuracy, Image Quality and Radiation Dose of 64-Slice Dual-Source CT in Daily Practice: a Single Institution's Experience

Objective

We wanted to evaluate the image quality, diagnostic accuracy and radiation exposure of 64-slice dual-source CT (DSCT) coronary angiography according to the heart rate in symptomatic patients during daily clinical practice.

Materials and Methods

We performed a retrospective search for the DSCT coronary angiography reports of 729 consecutive symptomatic patients. For the 131 patients who underwent invasive coronary angiography, the image quality, the diagnostic performance (sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV] for detecting significant stenosis ≥ 50% diameter) and the radiation exposure were evaluated. These values were compared between the groups with differing heart rates (HR): mean HR < 65 or ≥ 65 and HR variability (HRV) < 15 or ≥ 15.

Results

Among the 729 patients, the CT reports showed no stenosis or insignificant coronary artery stenosis in 72%, significant stenosis in 26% and non-diagnostic in 2%. For the 131 patients who underwent invasive coronary angiography, 95% of the patients and 97% of the segments were evaluable, and the overall per-patient/per-segment sensitivity, the perpatient/per-segment specificity, the per-patient/per-segment PPV and the per-patient/per-segment NPV were 100%/90%, 71%/98%, 95%/88% and 100%/97%, respectively. The image quality was better in the HR < 65 group than in the HR ≥ 65 group (p = 0.001), but there was no difference in diagnostic performance between the two groups. The mean effective radiation doses were lower in the HR < 65 or HRV < 15 group (p < 0.0001): 5.5 versus 6.7 mSv for the mean HR groups and 5.3 versus 9.3 mSv for the HRV groups.

Conclusion

Dual-source CT coronary angiography is a highly accurate modality in the clinical setting. Better image quality and a significant radiation reduction are being rendered in the lower HR group.     

64层螺旋CT对下肢动脉疾病的诊断及其临床价值

目的 探讨64层螺旋CT对下肢动脉狭窄闭塞性疾病的诊断价值. 资料与方法 对40例下肢动脉闭塞性疾病患者行64层CT容积扫描,15例1周内同时行数字减影血管造影（DSA）.将下肢血管分成8段,每段血管的狭窄程度被分为：正常、轻度狭窄、中度狭窄、重度狭窄、闭塞5个级别.将DSA与CTA结果进行比较. 结果 共对198个动脉段进行研究,对其狭窄程度显示一致的有191个,被CTA高估6个,低估1个.一致性检验Kappa值为0.953,P=0.017＜0.05,两者分析结果的一致性较好. 结论 64层螺旋CTA是下肢动脉狭窄硬化性疾病的可靠评估方法.     

房颤患者的64层CTCA:平均心率对图像质量和最佳重建期相的影响

目的:评价房颤患者64层螺旋CT冠状动脉成像中平均心率对最佳图像重建时相和图像质量的影响.方法:58例房颤患者行64层螺旋CT冠状动脉成像,扫描前均未服用美托洛尔.血管图像质量分为好、中等和差.分析平均心率和患者总体图像质量之间的相关性,采用判别分析法计算获得总体图像质量为好和中等的平均心率阈值和最佳重建时相在收缩末期的平均心率阈值.结果:平均心率和患者总体图像质量之间呈负相关(r=-0.43,P=0.001);患者总体图像质量为好和中等的平均心率阈值分别为80次/min和95次/min;最佳重建时相在收缩末期的平均心率阈值为85次/min.结论:控制患者平均心率在一定阈值以下并结合舒张中期蕈建.能保证房颤患者64层螺旋CT冠状动脉成像获得较高的图像质量.